Because the are *namespace* URIs, not *vocabulary* URIs. They were
never intended to be expanded by concatenating the expanded prefix with
the value after the colon. QNames are never concatenated - they are
treated as a tuple. CURIEs are ALWAYS concatenated, but CURIE prefixes
associate a prefix with a string that maps into a vocabulary. This is
the essential difference between QNames and CURIEs, at least with regard
to how they are used in RDFa.
Christoph LANGE wrote:
> On Thursday 22 January 2009 12:59:08 Shane McCarron wrote:
>> It basically has to do with dereferencing the resulting URI when you use
>> a QName or CURIE (e.g., xsi:lala should dereference to
>> http://www.w3.org/2001/XMLSchema-instance#lala - basically it has to do
>> with how the resource at the end of the namespace URI is constructed,
>> and how its components are accessed. If the resource masquerades as a
>> folder, then http://www.w3.org/2001/XMLSchema-instance/lala will
>> magically return the description for lala. If it masquerades as a
>> document, then http://www.w3.org/2001/XMLSchema-instance#lala will
>> return the complete resource and there will be a ID within that resource
>> that corresponds to lala.
>
> Thanks, but doesn't this explanation just cover the "hash vs. slash" issue?
> What I was actually wondering about was the case when a namespace URI neither
> ends with hash nor slash. Suppose
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance", what would xsi:lala
> expand to? Nothing reasonable, I suppose, so why do such namespace URIs
> exist?
>
> Cheers,
>
> Christoph
>
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Shane P. McCarron Phone: +1 763 786-8160 x120
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